A large and growing population of users enjoys entertainment through the consumption of media items, including electronic media, such as electronic books (also referred to herein as ebooks), electronic newspapers, electronic magazines, other electronic publications, audio books, and digital video. Users employ various electronic devices to consume such media items. Among these electronic devices are electronic book readers, cellular telephones, personal digital assistants (PDAs), portable media players, tablet computers, electronic pads, netbooks, desktop computers, notebook computers, and the like.
One common method of obtaining these electronic media items, such as digital video, is by downloading or streaming the digital video from a content provider over a network. Downloading and streaming both include receiving media data on a local system from a remote system, however, streaming generally indicates that the media data is used nearly immediately as it is received (while the transmission is still in progress) and may not be stored long-term, whereas downloading implies that the media data is only usable when it is received in its entirety. In order to provide a high quality service to the user, one goal is to achieve a secure connection between the service provider and the user device while minimizing the use of resources such as time and network bandwidth.
Many current streaming or download services, over both wired and wireless connections, base their security on application layer security, such as Hypertext Transfer Protocol Secure (HTTPS), Transport Layer Security (TLS), or Secure Sockets Layer (SSL). Forming secure channels using these protocols increases the overhead on the system, as multiple communications may be sent between the user device and the content provider. For example, the user device may send a request to stream a digital video and the content provider may have to authenticate the user, generate a unique encryption key, and send the encryption key back to the user device. The user device may acknowledge receipt of the encryption key, and only then does the content provider encrypt the digital video with the encryption key and start streaming the encrypted video data to the user device. These multiple exchanges may introduce a significant time delay between when the user requests the digital video and when he receives usable data and also take up valuable bandwidth. These factors may be of particular concern in wireless communications systems.